Mar.4 (GMM) At the front of the field in 2012, before a single racing lap has even turned, the well-known formula one arms-race has already begun.

As the last days of pre-Melbourne testing are counted down in Barcelona, Red Bull and McLaren unveiled major evolutions to their recently-launched new cars.

On the RB8, the major difference was the Sauber-style exhaust, after designer Adrian Newey was reportedly "impressed" with the 2012 solution devised by the Swiss midfield team.

"It's effectively a completely new (Red Bull) car," said the BBC's technical analyst Gary Anderson, according to the Guardian.

The high-profile Red Bull upgrade was the perfect time for McLaren to quietly unveil its own heavily modified car, Germany's Auto Motor und Sport reported.

"Did you see that McLaren have rebuilt half their car?" Force India technical director Andrew Green is quoted as saying.

One new innovation on the MP4-27, apparently, is a Mercedes-like front wing W-duct.

"The upgrade is a major step forward; better than we expected," said Jenson Button.

Elsewhere, the noises are not so positive: Ferrari stridently denied internet rumours Felipe Massa has been sacked, and then gagged both the Brazilian and his teammate Fernando Alonso from speaking to the media.

"The decision has been taken to keep the whole team fully focused on the job and there is not any polemic intent behind it," the team insisted.